1. Field of the Invention
The present invention relates to systems and methods of local organ perfusion of tumors or other serious conditions with one or more high dose treatment substances, isolating the venous outflow, collecting it, filtering it, and returning it to the body after removing the high dose treatment substance(s).
2. Background Art
There are several methods of treating cancerous tumors including surgery, chemotherapy, focal ablation by delivery of various forms of energy, radiation, amongst others. Often, tumors are not resectable by surgery because they have spread into the surrounding tissues or to distant tissues such as the liver, lung, or brain. The treatment of metastatic disease to these organs is done with chemotherapy, focal surgical resection and focal ablation when there are only a few lesions, and occasionally with radiation. Oftentimes, the metastatic disease is diffuse and not amenable to surgery, radiation or focal ablation. This leaves chemotherapy as the only alternative, and the effectiveness of the chemotherapy is limited by the systemic toxicities cause by the drug including bone marrow suppression, neutropenia, nausea, diarrhea, anorexia, wasting, cachexia, bacterial or viral overgrowth amongst others.
A system, process, and method of isolated perfusion of organs with a very high dose of a chemotherapeutic agent, collection of the effluent venous blood from that organ before it enters the systemic circulation, filtering the chemotherapeutic agent from the collected blood, and returning the filtered blood without the chemotherapeutic agent to the systemic circulation has been described by Glickman in U.S. Pat. Nos. 5,817,046, 5,893,841, 5,897,533, 5,919,163, and 7,022,097 and by Bodden in U.S. Pat. No. 5,069,662 and which are incorporated herein by reference. This system is referred to as the Percutaneous Hepatic Perfusion (PHP) apparatus for the purpose of treating metastatic disease and primary tumors of the liver. In essence, a very high dose of a chemotherapeutic agent is infused into the hepatic artery over a period of time, usually from 30 minutes to an hour. The high dose chemotherapeutic agent perfuses the liver and is much more effective than a traditional systemic dose administered intravenously. This drug is taken up by the tumor and the remainder flows into the hepatic veins, which are a series of veins that drain from the liver into the upper inferior vena cava (IVC.) This blood which still contains toxic levels of the chemotherapeutic agent is collected by an isolation device which is part of this special apparatus (PHP). The hepatic venous blood isolation device is a double balloon system that is deployed in the inferior vena cava, the balloons being inflated above and below the hepatic veins, the hepatic venous effluent collected into a catheter and pumped through a filter outside the body that removes the chemotherapeutic agent, and returned to the superior vena cava via another catheter. A through return lumen, also referred to as a return channel, is provided to allow blood in the inferior vena cava from the lower body and kidneys to flow back to the heart while the balloons are occluding the vena cava.
While the current prior art apparatus is effective in treating the tumor or tumors of the liver, it is somewhat cumbersome to use, as the double balloons may occlude the renal and/or adrenal veins, and the balloons tend to occupy more space in the inferior vena cava than is desirable. Moreover, the through lumen that transmits blood from the lower inferior vena cava to the heart is not large enough to accommodate the volume of blood returning to the heart. This frequently results in a sudden drop in the patient's blood pressure, and occasionally a shock like condition. Since it is expected that the patient will need at least some level of resuscitation, an anesthesiologist is in attendance to deal with these problems. Obviously, the risk to the patient and the cost of the procedure increases dramatically because these problems with the prior art technology. This is significant, not only from the risk to the patient, but also because it may prevent interventionalists from pursuing this strategy of treatment for their patients and their referring physicians. There is the risk that these problems with the prior art device and technology may prevent this very effective system of therapy from being fully adopted by the medical community, thereby depriving thousands of patients who would have benefited from the therapy otherwise. There are significant problems that can result from these iatrogenically created complications such as renal and adrenal vein thrombosis, unstable perfusion of the heart, brain, and kidneys, resulting in heart attack, stroke, kidney damage amongst other complications, in a patient who is already compromised because of the underlying malignancy. These complications are the result of the use of the primitive balloon technology and method of occluding, altering, or re-directing blood flow in the human body.
The balloons of the prior art device limit the size of the through lumen as the expanded balloons must occupy most of the inferior vena cava to effectively isolate the hepatic veins. This limits the amount of blood that can be returned from the inferior vena cava to the right atrium, resulting in the problems noted in the above paragraph. The footprint of the expanded balloons, especially the caudal balloon, in the inferior vena cava is problematic as the distance between the more caudal hepatic veins and the renal/adrenal veins is frequently less than the footprint of the expanded balloon.
In reviewing a series of over 50 CT scans of the abdomen, the inventor has determined from measurements of the cavoatrial junction to the orifice of the left renal vein that the current prior art device of Glickman is likely to partially occlude the left renal vein in greater than ⅓ of the cases. If a 15 mm compensating factor is utilized for curvature and other measurement inaccuracies, then there would likely still be greater than 20% of cases in which the left renal vein would be at least partially covered by the caudal balloon of the current device.
Also, different diameter devices may be needed as measurement of the anteroposterior (AP) and transverse dimensions of the IVC revealed a great variation in those measurements. Average AP and transverse dimensions in the upper IVC, mid retrohepatic IVC and immediate supra renal vein IVC were 23.6 mm and 30.4 mm, 20.0 mm and 22.7 mm, and 20.2 mm and 28.3 mm, respectively. A minimal AP dimension of only 8 mm was present in one subject while a maximum AP dimension of 36 mm occurred in another subject. Transverse dimensions varied from 10.2 mm to 40 mm in different subjects. The measurements taken may not apply to populations of different ethnicity and may vary even more in those different populations and age groups. Moreover, within the same patient, the IVC measurements many times revealed a large oblong supradiaphragmatic IVC, a smaller more rounded mid retrohepatic IVC, and a tilted, oblong configuration of the IVC just above the renal veins. In fact, the tilted oblong configuration just above the renal veins was frequently tilted in the opposite direction from the tilted oblong configuration of the supradiaphragmatic IVC.